Need help for a 74 duster wiring harness **pics

No way to tell from al that BUT I CAN TELL YOU that a 76 is WAY DIFFERENT. For one thing a 76 uses an "external shunt" ammeter, so that much of the harness won't match for sure

EDIT I see it is out of a Challenger. You are on your own. There are many differences in wiring between the two. "I think" you are asking for trouble.

Only way to go about it (???is the bulkhead connector even the same? doubt it???)

.......would be to obtain factory wiring diagrams for both vehicles and do a wire by wire comparison

If you are as familiar with the wiring in these girls as I am you might pull this off but the very fact that you "asked this question" suggests you might be up to your neck.

WHAT IS the actual car and WHAT DO you have of the original harness, and WHAT IS actually wrong with it?